HexToRGBPerc

This is a user-defined function that you can copy and paste into your addon.

Takes a hex string (must be 6 char long!) and converts it to a RGB percent set (0.0-1.0)

local function HexToRGBPerc(hex)
	local rhex, ghex, bhex = string.sub(hex, 1, 2), string.sub(hex, 3, 4), string.sub(hex, 5, 6)
	return tonumber(rhex, 16)/255, tonumber(ghex, 16)/255, tonumber(bhex, 16)/255
end

Alternative Version

Takes a hex string (must be 3 or 6 chars long!) and converts it to a RGB percent set (0.0-1.0). If hex is invalid, return black (0,0,0).

local function HexToRGBPerc(hex)
    local rhex, ghex, bhex, base
    if strlen(hex) == 6 then
        rhex, ghex, bhex = strmatch('([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})', hex)
        base = 255
    elseif strlen(hex) == 3 then
        rhex, ghex, bhex = strmatch('([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])', hex)
        base = 16
    end
    if not (rhex and ghex and bhex) then
        return 0, 0, 0
    else
        return tonumber(rhex, 16)/base, tonumber(ghex, 16)/base, tonumber(bhex, 16)/base
    end
end